JPH1054949A - Optical interconnection device between boards - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical interconnection device between boards economically and exactly performing optical connection without necessitating exact control of the wavelength of a light source. SOLUTION: Light beam arrays 2-7 generated from surface light emitting arrays 2-2 having lens arrays 2-3 mounted on the end parts of the respective boards 2-1, are received by light deflection control array elements 2-5, the traveling direction of the light beam array is variably controlled for every individual beam and is made obliquely incident on mirrors 2-6. The light beam arrays 2-7 reflected by the mirrors 2-6 are received by photodetector arrays Z-4 having the lens arrays 2-3 and a light beam from a desired board is connected to the photodetector of the desired board.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultra-high-speed, ultra-high-density, high-capacity ATM switch LSI mounted on a board mounted with electrical components such as a bookshelf. The present invention relates to a board-to-board optical interconnection device for connecting ultra-large capacity signals using light.

[0002]

2. Description of the Related Art The connection between ATM switch boards which is currently put into practical use is based on electric wiring, and the performance is determined by the pin density of an electric connector and the speed of a signal that can be transmitted. The current connector pin density is about 1 pin / mm ² . To send an electric signal several centimeters at the current speed of 100 Mbps 1
About W is required, and it is necessary to consider heat dissipation. Another problem is that when high-speed signals pass between the boards, EMC noise is generated. Therefore, when connecting the boards with electric signals, several hundred Mbps, connector density 1 / mm ²
Is said to be the limit. However, signal speed and connector density tend to increase year by year, approaching this limit. In order to overcome this limitation, light-to-board interconnections have attracted attention. For optical interconnection between ATM switch boards or between units, an optical interconnection module in which a semiconductor laser array and a detector array are connected via an optical fiber array has been developed and is already in the commercial stage (see J. Nishikido). , S.Hino, S.Urushidani and K.Yamasak
i, "Demonstration of Optically Interconnected Swit
ching Network, "Globecom'93, pp. 1187-1191).

[0003] However, the throughput of the fiber type optical interconnection module is at most about several tens of Gbps, and in order to apply it to the optical wiring between ATM switch boards having a very large capacity of 1 Tbps to 10 Tbps in the future,
Insufficient capacity. Therefore, free space optical interconnection, in which a light beam is sent to free space and a light source and a detector are directly connected without passing through an optical fiber, has been studied as a promising candidate. Free-space optical interconnection eliminates interference between optical signals
It has excellent features such as ultra-high-density optical wiring, low skew, no electrical noise, and low optical coupling loss.

Various methods have been proposed for forming an ultra-large capacity ATM switch. The configuration method will be described with reference to FIG. Usually, as shown in the upper drawing of FIG.
The N × 2 switch 5-1 is used as a basic unit switch and N ×
An N-subnetwork LSI 5-2 (including MCM mounting) is manufactured and mounted on a board, the boards are arranged in an M-stage L-column bookshelf, and the boards are connected. 2
The wiring between the × 2 switches is wired by electricity in the board. The advantage of this mounting method is that once the basic N × N sub-network switch board is manufactured, the switch capacity can be freely expanded and reduced by arbitrarily changing the number of M stages and L rows. . When these boards are arranged in a bookshelf shape, parallel and cross wiring over the boards is required as shown in FIG.

On the other hand, there is a method in which the 2 × 2 basic unit switch 5-1 is cut out vertically as shown by a broken line (a) in FIG. 9 and mounted on one board. The wiring in this case is shown in FIG.
Parallel and cross wiring between adjacent boards as shown in FIG. Examples of this configuration include the SEED switch system 5 of digital reproduction type optical switch of Bell Labs, which has been studied for the purpose of large-capacity ATM switch, and the EARS switch (16 × 16 switch, four-stage configuration) of NTT. The advantage of this configuration is that wiring between chips and between boards is only between adjacent chips and between boards, which is suitable for ultrahigh-density wiring of light.

[0006] There are many reports of free space optical interconnections connecting adjacent boards.

For example, McGill's Hinton et al. (T. Szymanski and HSHinton, Archit) used a massively parallel free space optical interconnection and digital regenerative switch (SEED) for the backplane.
ecture of a Terabit Free-space photonic backplane,
The international conferece on optical computing
technical digest, OC'94, Edinburgh, Scotland, Augu
st 22-25, (1944) WD2 / 221) has been proposed.

[0008] In order to connect the parallel processors with light, NTT's Sakano et al. Have a low density and low speed, but arrange 4 × 4 LEDs and detectors on a board, and arrange four boards to be 20 Mbps free. Optical interconnection between boards adjacent to space is realized (T. Sakano, T. Matsum
oto, and K. Noguchi "Three-dimensional board-to-boa
rd free-space interconnects and their application
to the prototype multiprocessor system ^* C0SINE-II
I, Applied Optics, vol.34, pp.1815-1822, 1995).

Further, as a high-speed free space optical interconnection between adjacent boards, DZTsang of MIT uses a fine adjustment table to fly a collimated light beam from a semiconductor laser over 24 cm, and an optical interface of 20 channels at a speed of 1 Gbps per channel. Connection (DZTsang, "one-gigabit per second free-space
optical interconnection, "Applied Optics vol.29, 2
034-2037, 1990).

[0010] On the other hand, as an optical interconnection across the boards, an optical interconnection using a D-fiber which enables a bus connection between the boards (P.Healey, "Chapter 7").
Multidimensional Switching Systems in Photonics i
n Switching, Vol.II, "Edited by JEMidwinter, Pre
ssed by Academic Press (London)), optical interconnection using hologram as backplane, (RCKim,
"An Optical Holographic Backplane Interconnect sy
stem, J.Lightwave.Tech.vol.9, p.1650-1656,1991 JN
ishikido, S.Hino, S.Urushidani and K.Yamasaki, "De
monstration of Optically Interconnected Switching
Network, "Globecom'93, pp.1187-1191)
NTT's crescent moons and others connect the boards with optical fibers via optical couplers and distribute 1 Gbps clocks for the purpose of optical bus wiring between the boards (K. Itoh, R. Konno,
Y.Katagiri, and T.Mikazuki "Data Transmission Per
formance of an Optical Backboard Bus "Proc.of Japa
n IEMT pp.268-271 1995).

[0011]

In the above-mentioned conventional optical interconnection, the optical interconnection using the D fiber has a large loss, so that there is a problem that an amplifier must be installed in the middle.

[0012] In addition, in optical interconnection across a board using a fixed hologram as a backplane, unnecessary light of higher order such as 0th order, -1st order, ± 2nd order is generated in addition to desired light. There is a problem that the talk increases, and there is also a problem that the cost is too high to produce a large hologram of the entire backplane, and furthermore, the wavelength of the light source is controlled more accurately so that a desired optical connection can be made. To
There is a problem that it is difficult to align the light beam.

In an optical interconnection between boards in which optical fibers are wired using an optical coupler, the capacity is at most several (1).
There is a problem that it is controlled to 0 Gbps.

The present invention has been made in view of the above,
It is an object of the present invention to provide a board-to-board optical interconnection apparatus that does not require precise control of the wavelength of a light source, and enables economical and accurate optical connection between boards.

[0015]

To achieve the above object, according to the present invention, an optical interface between boards for exchanging signals between boards by mounting a board on which an electric circuit is mounted in a bookshelf shape. A connection device,
A mirror disposed at a predetermined distance from an end of the board, a light source array with a lens array attached to the end of the board and generating a light beam array, and a light beam array from the light source array. Receiving, variably controlling the traveling direction of the light beam array for each individual beam, and a light deflection control array element that is inclinedly incident on the mirror, and attached to an end of the board, and the light deflection control array element A light detector array with a lens array for controlling the traveling direction individually and receiving the light beam array reflected by the mirror is provided.

According to the first aspect of the present invention, a light beam array generated from a light source array having a lens array attached to an end of each board is received by a light deflection control array element, and the light beam array travels. The direction is variably controlled for each beam, and the light enters the mirror obliquely, the light beam array reflected by the mirror is received by the photodetector array with the lens array, and the light from the desired board is transmitted to the desired board. Connected to light detector.

The present invention according to claim 2 provides the present invention according to claim 1.
In the invention described above, the light deflection control array element is a liquid crystal microprism array having a structure in which liquid crystal is sandwiched between a transparent flat substrate provided with divided transparent electrodes and an alignment film, and a transparent microprism array plate. And

Further, the present invention according to claim 3 provides the invention according to claim 1.
In the invention described above, the light deflection control array element is a micromirror array capable of individually controlling the traveling direction of the light beam array by electrostatic force.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the light deflection control array element includes a prism or a mirror arranged in an array, and mechanically rotating the prism or the mirror. The gist of the present invention is to have a rotation control means for individually controlling the traveling direction of the light beam array.

The present invention according to claim 5 provides the present invention as claimed in claim 1.
In the invention described above, the light deflection control array element is a liquid crystal deflection control element having a structure in which a liquid crystal is sandwiched between array divided electrodes having windows.

Further, the present invention according to claim 6 provides the present invention according to claim 1.
In the invention described above, the gist is that the light source array with the lens array has a surface emitting laser array.

According to a seventh aspect of the present invention, in the first aspect, the light deflection control array element is a combination of a control array element having a predetermined deflection direction and a control array element having a variable deflection direction. It is a gist that it is.

The present invention described in claim 8 provides the present invention according to claim 7.
In the invention described, the control array element in which the deflection direction is predetermined is selected from the group consisting of a hologram element, a prism array element, and a mirror array element, and the control array element in which the deflection direction is variable,
Liquid crystal micro prism array, micro mirror array,
The gist of the invention is that it is selected from the group consisting of a liquid crystal deflecting element, a mechanical micromirror, and a mechanical prism.

Further, the present invention described in claim 9 is based on claim 1.
In the invention described in the above, the first board group, which is a group of boards mounted in a bookshelf shape, is not parallel to the first mirror, which is the mirror, outside one final end where a light beam travels. A second mirror is disposed at an angle, and the light beam reaching the second mirror is reflected and re-enters the first mirror, and the light beam is applied to the bookshelf between the boards of the first board group. The gist is that the spatial arrangement of the second mirror is determined so as to be incident on the detector array with the lens array of the second board group mounted in the shape.

According to the ninth aspect of the present invention, a second mirror is arranged outside one of the last ends of the first board group.
The light beam is reflected by the second mirror and re-enters the first mirror, and the light beam is applied to each lens of the second board group mounted in a bookshelf shape between the boards of the first board group. The light enters the detector array with the array.

According to a tenth aspect of the present invention, in the invention of the ninth aspect, the other one of the first and second board groups mounted on the bookshelf in a shape opposite to the one final end is opposite to the one final end. A third mirror is disposed at an outer side at an angle that is not parallel to the first mirror, and reflects a light beam reflected by the second mirror and reaching the third mirror to be reflected on the first mirror. The light beam is re-entered, and the light beam is incident on the detector array with the lens array of each of the third board group mounted in the form of a bookshelf between the boards of the first and second board groups. The gist is that the spatial arrangement of the mirror is determined.

In the present invention according to claim 10, the first aspect
And a third mirror disposed outside the other end of the other side of the second group of boards, and reflects the light beam reflected by the second mirror and reaching the third mirror to be reflected by the first mirror. The light beam is re-incident, and is incident on the detector array with the lens array of each of the third board group mounted in a bookshelf shape between the boards of the first and second board groups.

[0028]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing the configuration of an optical interconnection device between boards according to an embodiment of the present invention. The optical interconnection device between boards shown in FIG.
A plurality of boards are arranged in a bookshelf shape, and an optical interconnection means is provided below the arranged boards to bridge the boards.

In FIG. 1, 2-1 is a board on which an electric circuit is mounted, 2-2 is a surface emitting laser array, 2-3 is a collimated beam of light from the surface emitting laser array 2-2, or a collimated beam. A lens array for condensing the light, an optical detector array 2-4 for receiving the beam array, and a deflection control element 2-5 for individually controlling the direction of the light beam. ing.

The array pitch of the surface emitting laser array 2-2, the lens array 2-3, the light detector array 2-4, and the liquid crystal microprism array 2-5 is 1 mm, and the focal length of the lens array 2-3 is about 5 mm. It is. The surface emitting laser array 2-2, the lens array 2-3, and the liquid crystal microprism array 2-5 are integrated and mounted at an angle of about 5 to 20 degrees with respect to the board 2-1. 2-
Reference numeral 6 denotes a plane mirror that reflects a light beam, and 2-7 denotes a light beam.

The light beam emitted from the surface emitting laser array 2-2 has a divergence angle of about 10 degrees.
3, and is converted into a collimated light beam by the lens array 2-3. However, as the light beam propagates, its diameter expands, and when it propagates about 50 cm, the beam diameter becomes about 1 mm. The light beam emitted from the surface emitting laser array 2-2 equipped with the deflection control element 2-5 and the lens array 2-3 is emitted obliquely to the board 2-1. The deflection direction of the light beam is controlled by a liquid crystal microprism array 2-5, which is a deflection control element, and is reflected by a plane mirror 2-6. 4 is connected.

Although FIG. 1 shows only the light beam from the leftmost board for the sake of space, light beams are actually emitted from all the boards 2-1. Although only the light beam at the forefront is shown for convenience of the drawing, there are actually a plurality of light beams in the depth direction of the drawing. The light beam is emitted obliquely downward from the right side of all the boards, and its direction is controlled by a light deflection control element, so that complicated cross optical wiring is possible.

FIG. 2 is a diagram showing a detailed configuration of the liquid crystal microprism array 2-5 constituting the light deflection control array element used in the board-to-board optical interconnection device shown in FIG. This liquid crystal microprism array is described in, for example, the document “Katsuhiko Hirabayashi, Tsuyosh
i Yamamoto and Masayasu Yamaguchi, "Free-space opt
ical interconnections with liquid crystal micropri
sm arrays, "Appl.Opt., vol.34, pp.2571-2580, (199
5) ".

In FIG. 2, 1-1 is a plurality of light incident beam groups, 1-2-1 is a transparent flat plate substrate, and 1-2-2 is a transparent substrate (here, glass substrate) having a sawtooth-shaped microprism formed on one side. 1-3, a transparent electrode; 1-4, an alignment film; 1-5, a liquid crystal; and 1-6, a non-reflective coating.
1-7 is a power supply for driving the liquid crystal element, 1-8 is a variable resistor for adjusting the voltage applied to each prism, 1-9
Is a light outgoing beam group. The liquid crystal is in a parallel alignment (homogeneous alignment). The transparent electrode 1-3 on the transparent flat substrate 1-2-1 is divided for each beam. The light beam is incident on the inclined surface of the saw of the glass substrate 1-2-2.

For light having a polarization parallel to the liquid crystal, the refractive index n changes with the applied voltage.
It changes from ne to no. Since Δn (= ne−no) is usually about 0.2 to 0.25, the vertex angle of the prism is 2
For about 5%, it becomes possible to change the deflection direction of the outgoing light beam by applying a voltage. The deflection control array element for controlling the traveling direction of the beam array for each individual beam is ne.
When the Merck E-8 liquid crystal having a large difference between n and n is used, when the apex angle is 5 °, 10 °, 20 °, and 30 °, 1.2 °, 2.5 °, 5 °, and 8 ° are used, respectively. It is possible to change the light deflection direction to about °. By patterning the transparent electrode, the deflection direction of the light beam can be individually controlled.

As another light beam deflection control element, there is a micro mirror array. The structure is shown in FIG. S
A micromirror array is formed on an i-substrate by using a plasma etching technique. 7-1, an Si substrate; 7-2, an oxide film; 7-3, a mirror direction control electrode formed of polysilicon; 7-4, an Al mirror;
5 is an incident light beam group, and 7-6 is a light beam group reflected by the Al mirror. The Al mirror 7-4 is grounded, and the direction of the Al mirror 7-3 can be controlled by controlling the voltage applied to the mirror direction control electrode 7-3. It is shown that the angle can be changed continuously up to 4 degrees. This element can also individually control the deflection direction of the light beam array by controlling the voltage applied to each micromirror. For details, see the reference `` DRCollins,
JBSampsell, LJHornbeck, JMFlorence, P.Andre
w penze, and MTGately, "Deformable mirror device
spaticical light modulators and their applicabili
ty neural networks, "Applied Optics Vol.28, (1989)
pp.4900-4907 ".

As another light beam deflection control element, there is a liquid crystal deflection element. The liquid crystal layer has a structure in which the liquid crystal layer is sandwiched between divided electrodes having windows. By controlling the voltage applied to the divided electrodes, the liquid crystal layer has a refractive index distribution and deflects the light beam by about 10 degrees. Also in the case of this element, the deflection direction of each light beam can be controlled. The structure is shown in FIG. FIG.
4A is a top view of the liquid crystal deflecting element, FIG.
(C), (d) and (e) are cross-sectional views. 8-1A,
8-1B, 8-1C, and 8-1D are Al electrodes, 8-2 is a glass substrate, and 8-3 is a liquid crystal layer. 8-4 is incident light, 8
Reference numeral -5 denotes the outgoing light. Here, when no voltage is applied, the liquid crystal is homeotropically oriented perpendicular to the substrate. When the voltage polarity applied to the Al electrodes 8-1A to 8-1D is changed to + and-, the orientation distribution of the liquid crystal molecules changes, thereby changing the refractive index distribution and deflecting the incident light beam. 4 (b), (c), (d),
(E) shows how the light beam is deflected when the voltage applied to the Al electrodes 8-1A to 8-1D is changed to + and-. The traveling direction of the light beam can be controlled by changing the polarity and magnitude of the voltage applied to each electrode. For details, see the document "A. Sasaki and T. Ishibashi," Liquid-crys
tal light deflector ", Electronics Lett., vol.10, (1
979) p.293-294 ".

Other light beam deflecting elements include those that mechanically rotate a prism and those that rotate a mirror. Each structure is shown in FIG. 5 and FIG. In FIG. 5, 9-1 is a microprism column, 9-2 is a plate holding them, 9-3 is a screw for rotating the microprism 9-1, 9-4 is an incident light beam group, and 9-5 is refraction. FIG. By adjusting the rotation of each microprism 9-1, the traveling direction of the refracted light beam group can be controlled.

In the mechanical rotating mirror shown in FIG. 6, 10-1 is a micromirror plate, 10-2 is a plate holding these, 10-3 is a screw for rotating the micromirror 10-1, and 10-4 is incident light. Beam groups 10-5 are outgoing light beam groups. Each micro mirror 10-1
The traveling direction of the reflected light beam group can be controlled by adjusting the rotation of.

FIG. 7 is a diagram showing a configuration of an optical interconnection device between boards according to another embodiment of the present invention.
The optical interconnection device between boards shown in FIG.
In the embodiment shown in FIG.
2. A notch space 3-1 is provided at an end of each board 2-1 to which the lens array 2-3, the light deflection control element 2-5, and the light detector array 2-4 are attached. Is configured so that the optical beam array 2-7 passes through the board and realizes an optical wiring across the boards. 7A shows the entire configuration between the boards, and FIG. 7B shows the surface emitting laser array 2-2, the lens array 2-3, and the light deflection control element 2 attached to the end of each board. -5 is shown enlarged.

In FIG. 7, the surface emitting laser array 2-2
Are arranged in a two-dimensional array at a pitch of 1 mm on a substrate 3-2 by solder bumps, and a microlens array 2-3 of a 1 mm pitch is further mounted thereon, and a liquid crystal microprism array is further mounted thereon. 2-5 are mounted. Since the light beams do not interfere with each other, high-density optical wiring is possible.

As an example of a typical interconnection,
When the distance between the mirror and the end of the board is 30 mm, the variable deflection angle range of the deflection control element is 5 degrees (corresponding to the vertical angle of the liquid crystal microprism array of 20 degrees), and the output angle and the shortest arrival board when the array pitch is 1 mm The relationship between the distance and the longest distance, the number of reachable boards, and the number of array stages is shown in FIG.
(B) and (c) show. Here, the distance between the boards was 30 mm. In general, the diameter of a light beam increases with its propagation distance. The maximum reach of a 1 mm pitch light beam array depends on the diameter of the surface emitting laser when one lens array is used, but is about 50 cm. When two lens arrays are used, the maximum reach is reached. The distance is about 80 cm. In the figure, the hatched portions indicate the areas restricted by the beam spread.

As shown in FIG. 8, when a light beam array of two lens systems is used, the number of arrays is two and the number of arrays is 15 to 38 cm (board spacing is assumed to be 30 mm). It can be seen that is possible. Actually, there are various requirements for the cross-board optical interconnection, and it is necessary to adjust the emission angle according to the requirements. By adjusting the variable resistors connected to the liquid crystal microprism array, it is possible to connect individual light beams to a desired light detector. The position and inclination of the board are shifted by the insertion and removal of the board.
When a beam having a diameter of mm is used, the deviation is within 10%, which is not a problem.

FIG. 11 is a diagram showing a configuration of an optical interconnection device between boards according to another embodiment of the present invention. The optical interconnection device between boards shown in FIG.
In the embodiment shown in FIG. 1, the deflection control element 2-5
A different point is that a fixed prism array 11-1 is provided on the above, and other configurations and operations are the same as those shown in FIG.

The fixed prism array 11-1 is set so that the apex angle is refracted corresponding to the optical wiring of each beam. Further, the deflection control element 2 disposed below the fixed prism array 11-1.
Reference numeral -5 uses a liquid crystal prism array capable of arbitrarily selecting a deflection direction for fine adjustment.

With this configuration, the disadvantage that the variable angle of the deflection control element 2-5 whose deflection direction is variable is small can be solved. That is, the wiring of light is mainly performed by the fixed prism array 11-1, and the misalignment or the like is corrected by the liquid crystal prism array element 2-5, which is a variable deflection control element, so that accurate alignment can be performed. In addition, since the liquid crystal prism array is simply used for correcting the beam direction, the apex angle can be set as low as several degrees, so that the liquid crystal layer can be made shallow and the response speed can be increased to several tens of ms.

In the above description, the case where the liquid crystal microprism is used has been described. However, the same effect can be obtained by using the micromirror array, the liquid crystal deflecting element, the mechanical micromirror, and the mechanical microprism described above.

As the fixed deflection control element, a hologram element, a prism array element, a mirror array element or the like can be used. As the variable deflection control element,
A liquid crystal prism array, a micromirror array, a liquid crystal deflecting element, a mechanical micromirror, a mechanical prism, or the like can be used, or both can be combined.

FIGS. 12 and 13 are a perspective view and a sectional view, respectively, showing the configuration of an optical interconnection device between boards according to still another embodiment of the present invention. The board-to-board optical interconnection device shown in FIG. 3 is configured by tilting the surface emitting laser array 2-2, lens array 2-3, and deflection control element 2-5 with respect to the board 2-1 in the embodiment shown in FIG. Special mounting was necessary because mounting was necessary, and it was configured so that what could be caused by many difficulties when mounting the mount on the board can be mounted in parallel, thereby eliminating many difficulties It was done.

12 and 13, reference numeral 12-1 denotes a surface emitting laser, reference numeral 12-2 denotes a lens array, and reference numeral 12-3 denotes a structure in which two liquid crystal prism arrays are bonded to each other at right angles. Each of the prism arrays has a taper. It is attached. 1
Reference numeral 2-4 denotes an open space provided under the board for passing a light beam, 12-5 denotes a light beam group, and 12-
Reference numeral 6 denotes a mirror, 12-7 denotes a detector array, and 12-8 denotes a tapered glass.

In the optical interconnection device between boards configured as described above, the surface emitting laser 12-1, the lens array 12-2, and the liquid crystal prism array 12-3 can be mounted in parallel with the board. Instead, a tapered glass substrate is used on the back surface of the liquid crystal prism array, whereby the light beam is refracted obliquely downward and emitted.

In this embodiment, the liquid crystal prism array is used for the optical wiring. However, a micromirror array, a liquid crystal deflecting element, a mechanical micromirror, or a mechanical prism may be used as a variable deflection control element.
One of a hologram element, a prism array element, and a mirror array element is used as a fixed deflection control element, and a liquid crystal prism array, a micro mirror array, a liquid crystal deflection element, a mechanical micro mirror, and a mechanical prism are used as variable deflection control elements. And one of them may be used in combination.

FIG. 14 is a diagram showing a configuration of an optical interconnection device between boards according to still another embodiment of the present invention. The board-to-board optical interconnection device of the present embodiment is provided with a prism mirror 14-4 so that the surface emitting laser and the lens array can be mounted in parallel to the board in the embodiment shown in FIG. Is provided with a variable liquid crystal prism array 14-5 for correction and a fixed prism array 14-6 on the lower surface.

That is, in FIG. 14, 14-1 is a board, 14-2 is a surface emitting laser, 14-3 is a lens array, 14-4 is a prism mirror, 14-5 is a liquid crystal prism array, and 14-6 is fixed. Prism array, 14-7
Is a light beam, 14-8 is a detector array, and 14-9 is a mirror.

In the board-to-board optical interconnection device of the present embodiment, the light beam emitted from the surface emitting laser 14-2 mounted parallel to the board 14-1 is emitted perpendicularly to the board, and the light beam is emitted to the lens array 14-3. After passing through, the angle is bent by 90 degrees by the prism mirror 14-4, and goes downward. The deflection direction of each beam is controlled by a liquid crystal prism array 14-5 provided on the lower surface of the prism mirror 14-4. Further, a liquid crystal prism array 1
4-5. Fixed prism array 14 provided underneath
The light beam is deflected by 6 to reach the desired light detector array 14-8.

The apex angle of the fixed prism array 14-6 is
Although it is preset according to each position, the light beam may reach a place slightly different from the target position due to misalignment at the time of mounting, error of the apex angle at the time of processing the prism, etc. The liquid crystal prism array 14-5 is provided to correct this. Therefore, since the liquid crystal prism array 14-5 does not need to largely deflect the light beam, a prism substrate having a small apex angle (several degrees) can be used. Therefore, as described above, the response speed of the liquid crystal microprism can be increased.

In the above embodiment, the prism array is used for main optical wiring and the liquid crystal prism array is used for correction. However, as a variable deflection control element, a micro mirror array, a liquid crystal deflection element, a mechanical micro mirror, a mechanical prism May be used. Further, one of a prism array, a hologram element, and a mirror array element is used as a fixed deflection control element, and a liquid crystal prism array, a micro mirror array, a liquid crystal deflection element,
One of a mechanical micromirror and a mechanical prism may be used, and both may be used in combination.

FIG. 15A is a diagram showing a configuration of an optical interconnection device between boards according to still another embodiment of the present invention. The board-to-board optical interconnection device shown in the figure is provided with a second mirror 15-4 outside the last end of the board group where the light beam travels, and reflects the light beam with the mirror. , And is incident on each detector array of the second board group.

In FIG. 15A, 15-1 is a first board group, 15-2 is a second board group, 15-3 is a first mirror arranged horizontally, and 15-4 is a first mirror. 15-5, a second light beam group connecting the first board group, and 15-6, a second mirror arranged substantially perpendicular to the first mirror.
Is a light beam group which is reflected by the mirror 15-4 and connects the second board group.

In the board-to-board optical interconnection apparatus shown in FIG. 1, as shown in FIG. 15B, the light beam reflects between the first mirror 15-3 and the first board 15-1. Go to the right side, but there is a large space between the boards, and the mounting density is low.

Accordingly, in the board-to-board optical interconnection apparatus of the present embodiment, as shown in FIG. 15A, the second mirror 15- is mounted on the right end of the board group outside the final end in the traveling direction of the light beam. By properly arranging the mirrors 4 spatially, the first board group 15-1 and the first mirror 15-3
The second mirror 15-4 reflects the light beam traveling while reflecting between the first board group 15-1 and the second board group 15-2 mounted between the first board group 15-1 and the first mirror. 15-
By turning back in the opposite direction while reflecting between the light source and the light source 3, the light beam interconnection is used even in the case of the turning back. With this configuration, the mounting density of the board can be doubled.

By providing the third mirror at the left end of the board group in the same manner, the light beam group can be reflected again, and the mounting density can be tripled. Also, the second and third mirrors need not be vertical, but may be tilted as long as the reflected light beam can reach the desired board. If the mirror is tilted, the angle of tilt may be adjusted instead of adjusting the position.

[0064]

As described above, according to the present invention,
A light beam array generated from a light source array with a lens array attached to the end of each board is received by a light deflection control array element, and the traveling direction of the light beam array is variably controlled for each individual beam and tilted to a mirror. And the light beam array reflected by the mirror is received by the photodetector array with the lens array, so that it is not necessary to precisely control the wavelength of the light source as in the prior art, and it is economically possible to obtain an accurate beam. By the alignment, light from a desired board can be optically connected to a photodetector of the desired board across the boards.

According to the present invention, the light deflection control array element is a combination of a control array element having a predetermined deflection direction and a control array element having a variable deflection direction. The element does not need to largely deflect the light beam, a prism substrate having a small apex angle can be used, and the response speed can be increased.

Further, according to the present invention, the second and / or third mirrors are arranged outside the final end of one or / and the other of the first board group, and the mirror reflects the light beam to reflect the light beam. The light beam re-enters the first mirror and the light beam enters the detector array with the lens array of each of the second and / or third boards mounted in a bookshelf shape between the boards of the first board. Therefore, the mounting density of the board can be increased.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of an optical interconnection device between boards according to an embodiment of the present invention.

FIG. 2 is a diagram showing a detailed configuration of a liquid crystal microprism array constituting an optical deflection control array element used in the optical interconnection device between boards shown in FIG.

FIG. 3 is a diagram showing a detailed configuration of a micromirror array constituting an optical deflection control array element used in the board-to-board optical interconnection device shown in FIG. 1;

FIG. 4 is a diagram showing another detailed configuration of the light deflection control array element used in the board-to-board optical interconnection device shown in FIG. 1;

5 is a diagram showing still another detailed configuration of an optical deflection control array element used in the optical interconnection device between boards shown in FIG. 1;

FIG. 6 is a diagram showing another detailed configuration of the optical deflection control array element used in the optical interconnection device between boards shown in FIG. 1;

FIG. 7 is a diagram showing a configuration of an optical interconnection device between boards according to another embodiment of the present invention.

FIG. 8 shows the relationship among the output angle and the shortest distance, the longest distance, the number of reachable boards, and the number of array stages of the arrival board in a typical interconnection example of the optical interconnection apparatus between boards shown in FIGS. 1 and 7; FIG.

FIG. 9 is a diagram showing a configuration of a conventional ATM switch.

FIG. 10 is a diagram showing optical connection between boards when a conventional ultra-large capacity ATM switch is manufactured.

FIG. 11 is a diagram showing a configuration of an optical interconnection device between boards according to another embodiment of the present invention.

FIG. 12 is a perspective view showing a configuration of an optical interconnection device between boards according to still another embodiment of the present invention.

13 is a cross-sectional view showing a configuration of the optical interconnection device between boards shown in FIG.

FIG. 14 is a diagram showing a configuration of an optical interconnection device between boards according to still another embodiment of the present invention.

FIG. 15 is a diagram showing a configuration of an optical interconnection device between boards according to still another embodiment of the present invention.

[Explanation of symbols]

 2-1 Board 2-2 Surface emitting laser array 2-3 Lens array 2-4 Optical detector array 2-5 Deflection control element (liquid crystal microprism array) 2-6 Planar mirror 11-1 Fixed prism array 15-1 1st board group 15-2 Second board group 15-3 First mirror 15-4 Second mirror

Claims (10)

[Claims] 1. A board-to-board optical interconnection device for mounting a board on which an electric circuit is mounted in a bookshelf and exchanging signals between the boards, wherein the board is provided at a predetermined distance from an end of the board. A light source array with a lens array attached to an end of the board for generating a light beam array, receiving a light beam array from the light source array, and changing a traveling direction of the light beam array for each beam. And a light deflection control array element that is variably controlled to be incident on the mirror at an angle, and is attached to an end of the board, the traveling direction is individually controlled by the light deflection control array element, and the light is reflected by the mirror. A board-to-board optical interconnection device having a photodetector array with a lens array for receiving a light beam array . 2. The light deflection control array element is a liquid crystal microprism array having a structure in which liquid crystal is sandwiched between a transparent flat substrate provided with divided transparent electrodes and an alignment film, and a transparent microprism array plate. Claim 1
The optical interconnection device between boards as described in the above. 3. The optical interconnection device between boards according to claim 1, wherein said light deflection control array element is a micromirror array capable of individually controlling the traveling direction of the light beam array by electrostatic force. 4. The light deflection control array element includes prisms or mirrors arranged in an array, and rotation control means for mechanically rotating the prisms or mirrors to individually control the traveling directions of the light beam array. The optical interconnection device between boards according to claim 1, further comprising: 5. The board-to-board optical interconnection device according to claim 1, wherein the light deflection control array element is a liquid crystal deflection control element having a structure in which a liquid crystal is sandwiched between array divided electrodes having windows. . 6. The optical interconnection device between boards according to claim 1, wherein said light source array with a lens array has a surface emitting laser array. 7. The inter-board board according to claim 1, wherein the light deflection control array element is a combination of a control array element having a predetermined deflection direction and a control array element having a variable deflection direction. Optical interconnection device. 8. The control array element in which the deflection direction is predetermined is selected from the group consisting of a hologram element, a prism array element, and a mirror array element. 8. The optical interconnection device between boards according to claim 7, wherein the optical interconnection device is selected from the group consisting of a liquid crystal microprism array, a micromirror array, a liquid crystal deflecting element, a mechanical micromirror, and a mechanical prism. 9. A first board group, which is a board group mounted in a bookshelf shape, is not parallel to the first mirror, which is the mirror, on the outer side of one final end where a light beam travels. A second mirror is disposed at an angle, and the light beam reaching the second mirror is reflected and re-enters the first mirror, and the light beam is applied to the bookshelf between the boards of the first board group. 2. The inter-board light according to claim 1, wherein the spatial arrangement of the second mirror is determined so as to be incident on each of the detector arrays with a lens array of the second board group mounted in a shape. Interconnection device. 10. A third mirror with respect to the first mirror, outside the other final end of the first and second board groups mounted on the bookshelf and opposite to the one final end. It is arranged at a non-parallel angle, reflects the light beam reflected by the second mirror and reaching the third mirror and re-enters the first mirror, the light beam being reflected by the first and second mirrors. The spatial arrangement of the third mirror is determined so as to be incident on the detector array with the lens array of each of the third boards mounted in a bookshelf shape between the boards of the boards. The optical interconnection device between boards according to claim 9.